A method for controlling and managing a bearer in a gateway of an IP-based mobile communication network is provided. A protocol message that must be sent between a mobility management entity and a gateway where a bearer exists is newly defined as context setup and IP allocation request/response messages, request/response messages for setup and release of a tunnel for service initiation and release, user equipment handover completion/completion acknowledgement messages, paging indication/response messages for a packet coming from a network, and multicast-service join/leave indication messages when the user equipment is powered on/off, resulting in high efficiency of signal protocol and efficient bearer management irrespective of separation or integration of physical nodes of the mobility management entity and the serving gateway.